Insulin resistance (IR) is a pathological condition in which cells either fail to respond normally to the hormone insulin or downregulate insulin receptors in response to hyperinsulinemia.
Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood glucose (blood sugar). Insulin is released by the pancreas in response to carbohydrates consumed in the diet. In states of insulin resistance, the same amount of insulin does not have the same effect on glucose transport and blood sugar levels. There are many causes of insulin resistance and the underlying process is still not completely understood. Risk factors for insulin resistance include obesity, sedentary lifestyle, family history of diabetes, various health conditions, and certain medications. Insulin resistance is considered a component of the metabolic syndrome. There are multiple ways to measure insulin resistance such as fasting insulin levels or glucose tolerance tests, but these are not often used in clinical practice. Insulin resistance can be improved or reversed with lifestyle approaches, such as exercise and dietary changes.